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HURRICANE JEANNE DISCUSSION NUMBER  15
NATIONAL WEATHER SERVICE MIAMI FL
5 AM EDT FRI SEP 25 1998
 
THE INTENSITY OF JEANNE REMAINS STEADY AT 90 KNOTS IN KEEPING WITH
SATELLITE ESTIMATES.  THE STORM IS APPROACHING AN UPPER LEVEL
TROUGH WHICH MAKES THE INTENSITY FORECAST MORE UNCERTAIN.  THE
VERTICAL SHEAR WILL PROBABLY INCREASE WITHIN THE NEXT 24 TO 36 HOURS
WHICH MAY ACT TO WEAKEN THE STORM.  THIS IS THE SHIPS MODEL
INTENSITY FORECAST.   NEVERTHELESS...IN SOME CASES INTERACTION WITH
A TROUGH CAN LEAD TO INTENSIFICATION.  THE GFDL MODEL HOLDS THE
INTENSITY NEAR 90 KNOTS THROUGH 36 HOURS BEFORE SLIGHT WEAKENING
BEGINS.  THIS IS THE INTENSITY FORECAST CHOSEN AND IS THE SAME AS
PREVIOUSLY.
 
JEANNE IS GRADUALLY TURNING TOWARDS THE NORTH IN RESPONSE TO THE
MIDDLE LATITUDE TROUGH TO THE WEST OF THE SYSTEM.  THE CURRENT
MOTION REMAINS 300/12 KNOTS.  THE SYSTEM IS FORECAST TO TURN TO THE
NORTHWEST AND THEN NORTHWARD BY 72 HOURS.  THIS MOTION CONTINUES TO
BE IN AGREEMENT WITH THE NOGAPS AND GFDL MODELS.
 
GROSS

 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     25/0900Z 18.4N  37.8W    90 KTS
12HR VT     25/1800Z 19.4N  39.5W    90 KTS
24HR VT     26/0600Z 21.3N  41.2W    90 KTS
36HR VT     26/1800Z 23.5N  42.4W    90 KTS
48HR VT     27/0600Z 26.0N  42.8W    85 KTS
72HR VT     28/0600Z 31.0N  42.5W    85 KTS
 
 
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